While medicine is the art of healing, the word medicinal refers to any substance which aids in that art. Many things can have medicinal properties, from pharmaceuticals produce artificially in labs by companies, to natural substances whose healing secrets have been passed down through generations within cultures. Even many common foods can have medicinal properties, such as the well-known medicine of chicken soup.

The development of new medications is big business in the United States and throughout the world. The discipline of medicinal chemistry is an intersection of several hard sciences, chemistry, pharmacology and biology. An understanding of all of these fields is crucial in order to develop new medicines for complex illnesses and conditions that will be of optimum benefit and producing the least negative side effects.